[Federal Register Volume 61, Number 70 (Wednesday, April 10, 1996)]
[Proposed Rules]
[Pages 15904-15906]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-8917]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-39-AD]


Airworthiness Directives; McDonnell Douglas Model DC-10-10 and 
DC-10-15 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain McDonnell Douglas Model 
DC-10-10 and DC-10-15 series airplanes. This proposal would require an 
inspection for evidence of missing chrome and for corrosion on the 
chrome surfaces, or verification that the forward trunnion bolts have 
been chrome plated in a specific manner; and rework or replacement of 
the bolts, if necessary. This proposal is prompted by a report of 
chrome flaking on the bearing surface of the trunnion bolts due to 
improper cleaning of the base material prior to chrome plating. The 
actions specified by the proposed AD are intended to prevent premature 
failure of the trunnion bolts and subsequent collapse of the main 
landing gear (MLG) as a result of chrome flaking and severe corrosion 
on the bearing surface and in the mechanical fuse.

DATES: Comments must be received by June 4, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-39-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule may be 
obtained from McDonnell Douglas Corporation, 3855 Lakewood Boulevard, 
Long Beach, California 90846, Attention: Technical Publications 
Business Administration, Department C1-L51 (2-60). This information may 
be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane 
Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount 
Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Maureen Moreland or Ron Atmur, 
Aerospace Engineers, Airframe Branch, ANM-120L, FAA, Los Angeles 
Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, 
California 90712; telephone (310) 627-5238 or (310) 627-5224; fax (310) 
627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address

[[Page 15905]]
specified above. All communications received on or before the closing 
date for comments, specified above, will be considered before taking 
action on the proposed rule. The proposals contained in this notice may 
be changed in light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 96-NM-39-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules 
Docket No. 96-NM-39-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On January 23, 1996, the FAA issued AD 96-03-05, amendment 39-9502 
(61 FR 5281, February 12, 1996), which is applicable to certain 
McDonnell Douglas Model MD-11 series airplanes and Model DC-10-30, DC-
10-40, and KC-10A (military) airplanes. For Model MD-11 series 
airplanes, that AD requires an inspection to determine the serial 
number of the forward trunnion bolts on the main landing gear (MLG), 
and rework or replacement of the bolts, if necessary. For Model DC-10-
30, DC-10-40, and KC-10A (military) airplanes, that AD requires an 
inspection for evidence of missing chrome and for corrosion on the 
chrome surfaces, or verification that the forward trunnion bolts have 
been chrome plated in a specific manner; and rework or replacement of 
the bolts, if necessary. That AD was prompted by reports of chrome 
flaking on the bearing surface of the trunnion bolts due to improper 
cleaning of the base material prior to chrome plating. The actions 
specified by that AD are intended to prevent premature failure of the 
trunnion bolts and subsequent collapse of the MLG as a result of severe 
corrosion on the bearing surface and in the mechanical fuse due to 
chrome flaking.
    Since the issuance of AD 96-03-05, the FAA has received reports 
indicating that the trunnion bolts on certain Model DC-10-10 and DC-10-
15 series airplanes were chrome plated during the same time frame using 
the same process as the trunnion bolts installed on airplanes affected 
by AD 96-03-05. Additionally, the FAA has received a report of chrome 
flaking on the bearing surface of the trunnion bolt installed on the 
MLG of a Model DC-10-10 series airplane.
    Subsequently, the FAA has reviewed and approved McDonnell Douglas 
Service Bulletin DC10-32-241, dated December 13, 1995, which describes 
procedures for a visual inspection for evidence of missing chrome and 
for corrosion on the chrome surfaces of the trunnion bolts, or 
verification that the forward trunnion bolts have been chrome plated in 
a specific manner. The service bulletin also provides procedures for 
certain rework or replacement of the bolts with serviceable parts, if 
necessary. Accomplishment of the rework or replacement will minimize 
the possibility of chrome flaking on the forward trunnion bolts.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require a visual inspection for evidence of missing 
chrome and for corrosion on the chrome surfaces, or verification that 
the forward trunnion bolts have been chrome plated in a specific 
manner; and rework or replacement of the bolts, if necessary. The 
inspection, verification, and certain corrective actions would be 
required to be accomplished in accordance with the service bulletin 
described previously. A portion of the rework would be required to be 
accomplished in accordance with the Component Maintenance Manual or a 
method approved by the FAA.
    There are approximately 139 McDonnell Douglas Model DC-10-10 and 
DC-10-15 series airplanes of the affected design in the worldwide 
fleet. The FAA estimates that 121 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 1 work 
hour per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$7,260, or $60 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this AD were not adopted.
    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities under 
the criteria of the Regulatory Flexibility Act. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

McDonnell Douglas: Docket 96-NM-39-AD.

    Applicability: Model DC-10-10 and DC-10-15 series airplanes, as 
listed in McDonnell Douglas Service Bulletin DC10-32-241, dated 
December 13, 1995; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or

[[Page 15906]]
repaired so that the performance of the requirements of this AD is 
affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (c) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent premature failure of the trunnion bolts and 
subsequent collapse of the main landing gear (MLG), accomplish the 
following:
    (a) For airplanes on which the forward trunnion bolts, part 
number (P/N) ARG7557-501, installed on the left and right MLG's, 
have accumulated 6,000 or more total flight hours, or 2,000 or more 
total flight cycles, as of the date of the inspection or 
verification required by paragraph (a)(1) or (a)(2), respectively, 
of this AD: Within 18 months after the effective date of this AD, 
accomplish either paragraph (a)(1) or (a)(2) of this AD, in 
accordance with McDonnell Douglas Service Bulletin DC10-32-241, 
dated December 13, 1995.
    (1) Remove the bolts and perform a visual inspection for 
evidence of missing chrome and for corrosion on the chrome surfaces, 
in accordance with the service bulletin.
    (i) If no evidence of missing chrome and no corrosion on the 
chrome surfaces are found, no further action is required by this AD.
    (ii) If any evidence of missing chrome or any corrosion on the 
chrome surfaces is found, prior to further flight, accomplish either 
paragraph (a)(1)(ii)(A) or (a)(1)(ii)(B) of this AD.
    (A) Remove the chrome plating on the trunnion bolt in accordance 
with the service bulletin; replace the plating in accordance with 
the Component Maintenance Manual (CMM), Chapter 20-10-02, Revision 
31, dated September 1, 1991, or in accordance with a method approved 
by a McDonnell Douglas Designated Engineering Representative (DER) 
who has been given a special delegation by the Manager, Los Angeles 
Aircraft Certification Office (ACO), FAA, Transport Airplane 
Directorate, to make such a finding; and reinstall the reworked bolt 
in accordance with the service bulletin.
    (B) Replace the trunnion bolt with a serviceable part in 
accordance with the service bulletin.
    (2) Verify whether the forward trunnion bolts, P/N ARG7557-501, 
installed on the left and right MLG's, have been chrome plated since 
original manufacture, in accordance with the CMM, Chapter 20-10-02, 
Revision 31, dated September 1, 1991, or in accordance with a method 
approved by a McDonnell Douglas DER who has been given a special 
delegation by the Manager, Los Angeles ACO, to make such a finding.
    (i) If the bolts have been chrome plated since original 
manufacture, in accordance with the CMM, Chapter 20-10-02, Revision 
31, dated September 1, 1991, or in accordance with a method approved 
by a McDonnell Douglas DER who has been given a special delegation 
by the Manager, Los Angeles ACO, to make such a finding: No further 
action is required by this AD.
    (ii) If any bolt has not been chrome plated since original 
manufacture, in accordance with the CMM, Chapter 20-10-02, Revision 
31, dated September 1, 1991, or in accordance with a method approved 
by a McDonnell Douglas DER who has been given a special delegation 
by the Manager, Los Angeles ACO, to make such a finding: Prior to 
further flight, accomplish the requirements of either paragraph 
(a)(1)(ii)(A) or (a)(1)(ii)(B) of this AD in accordance with the 
service bulletin.
    (b) For airplanes other than those identified in paragraph (a) 
of this AD: Within 18 months after the effective date of this AD, 
verify whether the forward trunnion bolts, P/N ARG7557-501, 
installed on the left and right MLG's, have been chrome plated since 
original manufacture, in accordance with the CMM, Chapter 20-10-02, 
Revision 31, dated September 1, 1991, or in accordance with a method 
approved by a McDonnell Douglas DER who has been given a special 
delegation by the Manager, Los Angeles ACO, to make such a finding.
    (1) If the bolts have been chrome plated since original 
manufacture, in accordance with the CMM, Chapter 20-10-02, Revision 
31, dated September 1, 1991, or in accordance with a method approved 
by a McDonnell Douglas DER who has been given a special delegation 
by the Manager, Los Angeles ACO, to make such a finding: No further 
action is required by this AD.
    (2) If any bolt has not been chrome plated since original 
manufacture, in accordance with the CMM, Chapter 20-10-02, Revision 
31, dated September 1, 1991, or in accordance with a method approved 
by a McDonnell Douglas DER who has been given a special delegation 
by the Manager, Los Angeles ACO, to make such a finding: Prior to 
further flight, accomplish the requirements of either paragraph 
(b)(2)(i) or (b)(2)(ii) of this AD in accordance with McDonnell 
Douglas Service Bulletin DC10-32-241, dated December 13, 1995.
    (i) Remove the chrome plating on the trunnion bolt in accordance 
with the service bulletin; replace the plating in accordance with 
the Component Maintenance Manual (CMM), Chapter 20-10-02, Revision 
31, dated September 1, 1991, or in accordance with a method approved 
by a McDonnell Douglas Designated Engineering Representative (DER) 
who has been given a special delegation by the Manager, Los Angeles 
ACO, FAA, Transport Airplane Directorate, to make such a finding; 
and reinstall the reworked bolt in accordance with the service 
bulletin. Or
    (ii) Replace the trunnion bolt with a serviceable part in 
accordance with the service bulletin.
    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Los Angeles ACO. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Los Angeles ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (d) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

    Issued in Renton, Washington, on April 4, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-8917 Filed 4-9-96; 8:45 am]
BILLING CODE 4910-13-P